Determinants of Hiv Transmission Among Children Born to Hiv-infected Mothers on Pmtct Program in Kilifi County: a Case Control Study

Abstract

BACKGROUND: Globally, mother to child elimination and prevention of human immunodeficiency virus transmission remains a public health concern. The transmission rate is still high especially in sub Saharan countries despite introduction of antiretroviral therapy to breastfeeding mothers and all HIV-positive pregnant women. Identification of significant risk factors of mother to child transmission is essential and might reduce the burden of pediatric HIV in terms of cost of treatment, morbidity and mortality. OBJECTIVE: To determine maternal risk factors related to HIV transmission among children born to HIV- infected mothers enrolled in PMTCT program in Kilifi County between July 2018 and June 2019 METHODS: This was a retrospective unmatched case control study covering a period of 1 year. Systematic random sampling was used to select medical records of 183 exposed infants (61 cases and 122 controls) with cases defined as HIV-positive mother enrolled in the PMTCT program with a confirmed HIV-positive infant and controls as HIV-positive mother enrolled in PMTCT program with a confirmed HIV-negative infant. Data on maternal and infant socio-demographic and exposure related factors was collected by use of a structured tool. Analysis was done using MS Excel and SPSS version 21. Proportions and frequency distribution was done in univariate analysis. In bivariate analysis, chi-square and logistic regression (odds ratio) was used to determine any association between categorical variables and to estimate the strength between exposure and outcome variable. RESULTS: The study showed a relationship between ANC attendance of the mothers and outcome of their infants’ HIV status. Majority of mothers (88%) to all infants sampled in the study had attended ANC at least once. All the mothers who had a HIV negative infant had attended ANC while 33% of those who had a HIV positive infant did not attend ANC. Knowledge of mother’s HIV status and outcome of their infants was not different between the cases and the control group. Majority of the mothers (95%) knew their HIV status prior to attending ANC. Seventy five (75%) of all the mothers had received Maternal HAART. Of the mothers who had a HIV positive infant 62% did not receive maternal HAART while of those who had a HIV negative infant only 3% did xi not receive maternal HAART. 82% of the mothers who were studied delivered at a health facility compared to 18% who delivered at home. 42% of the infants who tested HIV positive were delivered at home. Only 3% of the infants who were confirmed to be negative were delivered at home. Only 4 of the infants enrolled into the study did not receive ART prophylaxis and cotrimoxazole. For the infants who received ART prophylaxis, 88% received both NVP and AZT while 12% received only NVP. Out of the infants who tested HIV positive, 91% were on both NVP and AZT while 9% were on NVP alone. For those who tested HIV negative, 87% were on NVP and AZT while 13% were on NVP alone. CONCLUSION: The study established the importance of PMTCT service delivery in reduction of vertical transmission of HIV. ANC attendance, early diagnosis of maternal HIV, prompt initiation and adherence to HAART, skilled delivery of the HIV positive pregnant woman were all associated with reduction of mother to child transmission rate. Women who defaulted on the PMTCT cascade services had higher odds of having a HIV positive infant compared to women who accessed all the PMTCT services at the recommended time.